1. Department of Otolaryngology; University of Pittsburgh School of Medicine; Pittsburgh Pennsylvania U.S.A.
2. Department of Otolaryngology; Albert Einstein College of Medicine; Bronx New York U.S.A.
3. Department of Otolaryngology; Columbia University College of Physicians and Surgeons; New York New York U.S.A.
4. Department of Otolaryngology; Georgia Regents University; Augusta Georgia U.S.A.